To err is human. However, when physicians make mistakes, people can die. Most efforts to reduce the number of errors made by physicians begin with the premise that decisions reflect knowledge, attitudes, and external constraints. Based on insights from the behavioral science literature, as well as work done during my mentored career development award, I argue that heuristics (intuitive judgments) play an important role in the decision making of physicians - particularly for time-sensitive conditions (e.g. trauma triage, sepsis, stroke). When calibrated appropriately, these mental short cuts allow physicians to make decisions under conditions of time- pressure and uncertainty. However, when calibrated poorly, heuristics result in predictable errors in judgment. I propose developing and testing the effectiveness of an intervention to recalibrate heuristics, using serious game technology. This is an exceptionally innovative program of research. It challenges the current dogma about the rationality of physicians. It translates behavioral science principles about how people learn into new method of modifying physician judgment. It exploits advances in gaming technology to make the intervention enjoyable and generalizable. This research program is feasible because it leverages my ability to develop creative solutions to difficult clinical problems, to respond to challenges, and to establish productive collaborations across disciplines. If successful, it has th potential to save lives.